2,4,6-tricyclohexyl-1,3,5-trioxane;trimer of cyclohexane carbaldehyde;2,4,6-Tricyclohexyl-[1,3,5]trioxan;2,4,6-Tricyclohexyl-<1,3,5>trioxan;2,4,6-Tricyclohexyl-(1,3,5)-trioxan;2,4,6-Tricyclohexyl-1,3,5-trioxan
Acid-catalyzed aldol-Meerwein–Ponndorf–Verley-etherification reactions—access to defined configured quaternary stereogenic centers
摘要:
A novel asymmetric aldol-reduction-etherification process of aliphatic enolizable aldehydes is described. The intermediately formed aldol adducts-beta-hydroxyaldehydes-were reduced and transformed into the corresponding 1,3-diol ethers by external secondary alcohols at the same time. Thus, with the help of chiral secondary alcohols an access to optically active 1,3-diol ether is given. Furthermore, asymmetric cross-aldol-Meerwein-Ponndorf reactions of enolizable aldehydes can also be realized under these reaction conditions. Crown Copyright (C) 2011 Published by Elsevier Ltd. All rights reserved.
Acetonyltriphenylphosphonium bromide in organic synthesis: a useful catalyst in the cyclotrimerization of aldehydes
作者:Yung-Son Hon、Chia-Fu Lee
DOI:10.1016/s0040-4020(01)00588-9
日期:2001.7
Acetonyltriphenylphosphonium bromide (ATPB) is a useful catalyst for the cyclotrimerization of the aliphatic aldehydes under solvent-free condition. The aldehydes tethered with a variety of functionality such as olefin, ether, ester, bromide, azide and diester could also be cyclotrimerized under the catalysis of ATPB.
Antimony(<scp>v</scp>) cations for the selective catalytic transformation of aldehydes into symmetric ethers, α,β-unsaturated aldehydes, and 1,3,5-trioxanes
作者:Renzo Arias Ugarte、Deepa Devarajan、Ryan M. Mushinski、Todd W. Hudnall
DOI:10.1039/c6dt02121b
日期:——
acidity of [2][OTf] was exploited in the catalytic reductivecoupling of a variety of aldehydes into symmetric ethers of type L in good to excellent yields under mild conditions using Et3SiH as the reductant. Additionally, [2][OTf] was found to selectively catalyze the Aldol condensation reaction to afford α-β unsaturated aldehydes (M) when aldehydes with 2 α-hydrogen atoms were used. Finally, [2][OTf]
Stereoselective one-pot synthesis of highly differently substituted thiochromans
作者:Andrea Seifert、Rainer Mahrwald
DOI:10.1016/j.tetlet.2009.09.009
日期:2009.11
A highly stereoselective one-pot procedure to anti-configured thiochromans is described. This reaction functions at room temperature in the presence of catalytic amounts of trifluoroacetic acid. The transformation gives a selective but optional access to highly substituted thiochromans, which have been not attainable until now.
A High Yield Procedure for the Me3SiNTf2-Induced Carbon-Carbon Bond-Forming Reactions of Silyl Nucleophiles with Carbonyl Compounds: The Importance of Addition Order and Solvent Effects
We demonstrate the efficiency of Me3SiNTf2 (0.3-1.0 mol%) as a strong Lewis acid catalyst for the Mukaiyama aldol and Sakurai-Hosomi allylation reactions, and that the slow addition of carbonyl compounds to a solution of acid catalyst and Me3Si-Nu is very important for suppressing side products; this may be widely accepted as a common and reasonable general procedure for the Lewis acid-induced reaction of Me3Si-Nu with carbonyl compounds.
Homogeneousbimetallicsystems such as Co2(CO)8–Ru3(CO)12 and [Et4N][FeCo3(CO)12] show high catalytic activity for the hydroformylation of cyclohexene compared with Co2(CO)8 alone.